Jump to main content
Jump to site search

Issue 9, 2014
Previous Article Next Article

Porphyrin–cobaloxime complexes for hydrogen production, a photo- and electrochemical study, coupled with quantum chemical calculations

Author affiliations

Abstract

Two porphyrin–cobaloxime complexes; [{Co(dmgH)2Cl}{MPyTPP}] (1a) and [{Co(dmgH)2Cl}{ZnMPyTPP}] (2a) (dmgH = dimethylglyoxime, MPyTPP = 5-(4-pyridyl)-10,15,20-triphenylporphyrin) have been synthesised as model systems for the generation of hydrogen from water. Although initially envisaged as photocatalytic systems neither complex catalysed the reduction of water to hydrogen following irradiation. However, both complexes are molecular precursors for hydrogen evolution under electrochemical conditions. Turnover numbers for hydrogen production of 1.8 × 103 and 5.1 × 103 were obtained for 1a and 2a respectively following potentiostatic electrolysis at −1.2 V vs. Ag/AgCl while cobaloxime alone produced a turnover-number of 8.0 × 103. The photophysical properties of 1a and 2a were examined to provide an explanation for the lack of photochemical activity. These results, coupled with quantum chemical calculations, confirm that porphyrins fail to act as light-harvesting units for these systems and that the lowest energy excited states are in fact cobaloxime-based rather than porphyrin based.

Graphical abstract: Porphyrin–cobaloxime complexes for hydrogen production, a photo- and electrochemical study, coupled with quantum chemical calculations

Back to tab navigation

Supplementary files

Publication details

The article was received on 08 Nov 2013, accepted on 30 Dec 2013 and first published on 08 Jan 2014


Article type: Paper
DOI: 10.1039/C3DT53166J
Dalton Trans., 2014,43, 3576-3583

  •   Request permissions

    Porphyrin–cobaloxime complexes for hydrogen production, a photo- and electrochemical study, coupled with quantum chemical calculations

    J. C. Manton, C. Long, J. G. Vos and M. T. Pryce, Dalton Trans., 2014, 43, 3576
    DOI: 10.1039/C3DT53166J

Search articles by author

Spotlight

Advertisements